This invention relates to slimes treatment.
In mineral sands operations throughout the world, the removal of fine clay material, commonly called slimes, is necessary prior to the gravimetric concentration of the heavy minerals in the primary concentration stage. Although the removal of the slimes is readily achieved, and concentration of the slimes can be achieved in a thickener, the disposal of the thickened slimes remains a problem.
Various attempts have been made to co-deposit the slimes with the coarse tailings stream, but to date, no effective method has been demonstrated. This is partly due to the fact that the tailings are typically conveyed to the point of deposition in a slurry form and the water run-off assists in removing the slimes from the deposition point.
As the industry depletes more and more of the better mineral sands ore reserves, there is a need to exploit some of the reserves previously considered uneconomic. In many cases, the main hinderance to exploitation of these reserves is the high slimes content--in some cases over 25% of the in situ ore is slimes.